Dental crown-remover.



J. A. WEST.

DENTAL GROWN REMOVER.

APPLICATION FILED JUNE 19, 1913.

Patented Sept. 1, 1914.

THE L'RRls PETERS CQIPHOTO-LITHQ. WASHINGTON. D. c.

Jorrn ALDEN wnsr,. or nos nennns, CALIFORNIA.

. DENTAL cnown-nEr/iovnn.

I Specification of Letters Patent.

Application filed ll'une 19, 1913. 'ScriaI No. 774,705. I I

To all whom it may concern: I

Be it known that 1, JOHN ALnnN'lVns'r, a subject of the King'of the United Kingdom of Great Britain and Ireland, residing at Los Angeles, in the county of Los Angeles and State of California, have invented new and Useful Dental Grown-Remover,

of which the following is a specification.

My invention relates to dental devices for removing metal crowns, and particularly gold crowns, such as are ordinarily cemented over the outer surface of teeth.

The principal object of my invention is to provide means for removing such crowns without the necessity for cutting them or otherwise destroying their usefulness should it be desired to replace them as is often the case when it is necessary to treat the tooth after the crown has been in place some time.

Further objects and advantages will appear from the following specification.

Referring to the drawings which are for illustrative purposes only: Figure 1 is a plan view of my device. Fig. 2 is a sectional elevation along the line a2 m of Fig. 1. Fig. 3 is an elevation, partly in section, at right angles to the section of Fig.2. Fig. 4c is a perspective view of my device illustrating the method of operation.

Referring to the drawings, 1 is a jaw which contains a tooth 2, this tooth 2 being cut away as shown at 3 for the attachment of a crown 1 which is usually of gold although it may be made of other metal. This crown 41 is ordinarily fastened in place with cement 5. For the purpose of removing this crown I drill a hole 6 in the upper surface of the crown large enough for a screw 7 to pass through, the screw 7 thus resting on the top of the tooth 2. The screw 7 is provided with a knurled head 8 having holes 9 therein for the reception of a bar 10. The screw 7 passes through a nut 11. The nut 11 is provided with notches 12 arranged in the periphery thereof. The nut 11 is also provided with two openings 18 on the opposite sides of the screw 7 and hooks 14L are placed therein. These hooks are provided with a head 15 at the upper end, this head 15 being somewhat longer than the openings 13 to prevent the hook being pulled downwardly therethrough. The lower ends of the hooks 14 are provided with projections 16 for engaging the lower edge of the crown 4. Springs 17 are rigidly attached to the 14 m engagement with the lower edge of the crown. The hooks 1 1 are made detachable so thatdifferent lengths thereof may be used with the same nut and screw. The

Patented Sept.i1,1914.

nut 11 to hold the projections 16 ofthe hooks bar 10-is adaptedto engage the -holes'9' in the knurled head8 of the screw 7. In addition a wrench 18 having a hook 20 is provlded, this wrench being adapted to fit around the nut 11 and engage the notches 12 therein as shown in Fig. 4.

The method of operatlon of this device is as follows: The hole 6 having been drilled through the crown 4, the nut 11 is put in place in the mouth and the projections 16 of the hooks 14 are forced into place under the lower edges i of the crown 4. The knurled head 8 is then turned until the lower end of the screw 7 is firmly seated in the bottom of the hole 6. The bar 10 and the wrench 18 are then put in place, the nut 11 being held in position by the wrench 18, and the bar 10 being used to force the screw downwardly and pull the crown upwardly, thus removing it from the tooth YVhat I claim is 1. A dental crown remover comprising a nut, a screw passing through said nut, one end of said screw being :adapted to pass through an opening in a crown to be removed and engage t e top of the tooth, said nut having openings therethrough on opposide sides thereof, a headed hook in each opening in said nut depending downwardly therethrough and arranged to engage with the lower edge of the crown, and springs arranged to kee the hooks in engagement with the edge of the crown when the screw is actuated.

2. A dental crown remover comprising a nut, a screw passing through said nut, one end of said screw being adapted to pass through an opening in a crown to be removed to engage the top of the tooth,said nut having hook receiving openings therethrough on the opposite sides thereof, a hook in each opening in said nut depending downwardly therethrough to engage with the lower edge of said crown, a head on the upper end of each hook adapted to rest on the upper face of said nut, a spring secured to said. nut in each hook receiving opening, said springs being arranged to extend downwardly from said nut into engagement with the outer face of the respective hooks to keep said hooks in engagement with the edge of the crown when the screw is actuated.

3'. A dental crown remover comprising a nut provided with engagement means for receiving a holding device, said nut being provided with openings therethrough, a

screw passing through said nutprovided at one end with engagement means for an actuating device, the opposite end of saidv screw being adapted to pass through an opening inthe crown to be removed to engage with the top of a tooth, a hook in each opening in said nut depending downwardly therethrough to engage with the lower edge 15 of said crown, a head on the upper end of each hook adapted to rest on the upper face with the edge'of said crown when the screw 20 is actuated.

In'testimony whereof, I have hereunto set my hand at Los Angeles, California, this 13th day of June, 1913.

- JOHN ALDEN WEST. In presence of v FRED A. MANSFIELD, FORD WV. HARRIS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

\ Washington, D. C. 

